Salt or sugar for your injured brain? A meta-analysis of randomised controlled trials of mannitol versus hypertonic sodium solutions to manage raised intracranial pressure in traumatic brain injury

Fluid therapy and traumatic brain injury: A narrative review

Traumatic brain injury (TBI) is an important health and social problem. The mechanism of damage of this entity could be divided into two phases: (1) a primary acute injury because of the traumatic event; and (2) a secondary injury due to the hypotension and hypoxia generated by the previous lesion, which leads to ischemia and necrosis of neural cells. Cerebral edema is one of the most important prognosis markers observed in TBI. In the early stages of TBI, the cerebrospinal fluid compensates the cerebral edema. However, if edema increases, this mechanism fails, increasing intracranial pressure. To avoid this chain effect, several treatments are applied in the clinical practice, including elevation of the head of the bed, maintenance of normothermia, pain and sedation drugs, mechanical ventilation, neuromuscular blockade, controlled hyperventilation, and fluid therapy (FT). The goal of FT is to improve the circulatory system to avoid the lack of oxygen to organs. Therefore, rapid and early infusion of large volumes of crystalloids is performed in clinical practice to restore blood volume and blood pressure. Despite the relevance of FT in the early management of TBI, there are few clinical trials regarding which solution is better to apply. The aim of this study is to provide a narrative review about the role of the different types of FT used in the daily clinical practice on the management of TBI. To achieve this objective, a physiopathological approach to this entity will be also performed, summarizing why the different types of FT are used.

Hypertonic saline for traumatic brain injury: a systematic review and meta-analysis

BACKGROUND

Traumatic brain injury (TBI) causes mortality and long-term disability among young adults and imposes a notable cost on the healthcare system. In addition to the first physical hit, secondary injury, which is associated with increased intracranial pressure (ICP), is defined as biochemical, cellular, and physiological changes after the physical injury. Mannitol and Hypertonic saline (HTS) are the treatment bases for elevated ICP in TBI. This systematic review and meta-analysis evaluates the effectiveness of HTS in the management of patients with TBI.

METHODS

This study was conducted following the Joanna Briggs Institute (JBI) methods and PRISMA statement. A systematic search was performed through six databases in February 2022, to find studies that evaluated the effects of HTS, on increased ICP. Meta-analysis was performed using comprehensive meta-analysis (CMA).

RESULTS

Out of 1321 results, 8 studies were included in the systematic review, and 3 of them were included in the quantitative synthesis. The results of the meta-analysis reached a 35.9% (95% CI 15.0-56.9) reduction in ICP in TBI patients receiving HTS, with no significant risk of publication bias (t-value = 0.38, df = 2, p-value = 0.73). The most common source of bias in our included studies was the transparency of blinding methods for both patients and outcome assessors.

CONCLUSION

HTS can significantly reduce the ICP, which may prevent secondary injury. Also, based on the available evidence, HTS has relatively similar efficacy to Mannitol, which is considered the gold standard therapy for TBI, in boosting patients' neurological condition and reducing mortality rates.

A Brief Review of Bolus Osmotherapy Use for Managing Severe Traumatic Brain Injuries in the Pre-Hospital and Emergency Department Settings

Background: Severe traumatic brain injury (TBI) management begins in the pre-hospital setting, but clinicians are left with limited options for stabilisation during retrieval due to time and space constraints, as well as a lack of access to monitoring equipment. Bolus osmotherapy with hypertonic substances is commonly utilised as a temporising measure for life-threatening brain herniation, but much contention persists around its use, largely stemming from a limited evidence base. Method: The authors conducted a brief review of hypertonic substance use in patients with TBI, with a particular focus on studies involving the pre-hospital and emergency department (ED) settings. We aimed to report pragmatic information useful for clinicians involved in the early management of this patient group. Results: We reviewed the literature around the pharmacology of bolus osmotherapy, commercially available agents, potential pitfalls, supporting evidence and guideline recommendations. We further reviewed what the ideal agent is, when it should be administered, dosing and treatment endpoints and/or whether it confers meaningful long-term outcome benefits. Conclusions: There is a limited evidence-based argument in support of the implementation of bolus osmotherapy in the pre-hospital or ED settings for patients who sustain a TBI. However, decades’ worth of positive clinician experiences with osmotherapy for TBI will likely continue to drive its on-going use. Choices regarding osmotherapy will likely continue to be led by local policies, individual patient characteristics and clinician preferences.

An overview of systematic reviews on the pharmacological randomized controlled trials for reducing intracranial pressure after traumatic brain injury

BACKGROUND

There is a need for an overview of systematic reviews (SRs) examining randomized clinical trials (RCTs) of pharmacological interventions in the treatment of intracranial pressure (ICP) post-TBI.

OBJECTIVES

To summarize pharmacological effectiveness in decreasing ICP in SRs with RCTs and evaluate study quality.

METHODS

Comprehensive literature searches were conducted in MEDLINE, PubMed, EMBASE, PsycINFO, and Cochrane Library databases for English SRs through October 2020. Inclusion criteria were SRs with RCTs that examined pharmacological interventions to treat ICP in patients post-TBI. Data extracted were participant characteristics, pharmacological interventions, and ICP outcomes. Study quality was assessed with AMSTAR-2.

RESULTS

Eleven SRs between 2003 and 2020 were included. AMSTAR-2 ratings revealed 3/11 SRs of high quality. Pharmacological interventions included hyperosmolars, neuroprotectives, anesthetics, sedatives, and analgesics. Study samples ranged from 7 to 1282 patients. Hyperosmolar agents and sedatives were beneficial in lowering elevated ICP. High bolus dose opioids had a more deleterious effect on ICP. Neuroprotective agents did not show any effects in ICP management. RCT sample sizes and findings in the SRs varied. A lack of detailed data syntheses was noted. AMSTAR-2 analysis revealed moderate-to-high quality in most SRs. Future SRs may focus on streamlined reporting of dosing and clearer clinical recommendations.

CONCLUSIONS

PROSPERO-Registration: CRD42015017355.

The Optimal Dose and Concentration of Hypertonic Saline in Traumatic Brain Injury - A Systematic Review

Management of increased intracranial pressure in traumatic brain injury remains challenging in neurosurgical emergencies. The mainstay of medical management for increased intracranial pressure is hyperosmolar therapy with mannitol or hypertonic saline. Mannitol has been the “gold standard” osmotic agent for almost a century. Given its wide usage, there has been a dilemma of concern because of its adverse effects. Over the past few decades, hypertonic saline has become an increasingly better alternative. To date, there is no consensus on the optimal therapeutic dose and concentration of hypertonic saline for treating increased intracranial pressure. This systematic review aimed to compare the efficacy of hypertonic saline and mannitol in the management of traumatic brain injury and investigate the optimal dose and concentration of hypertonic saline for the treatment. Extensive research was conducted on PubMed, DOAJ, and Cochrane databases. Studies published within the last 20 years were included. Research articles in the form of meta-analyses, clinical trials, and randomized controlled trials were preferred. Those with ambiguous remarks, irrelevant correlations to the main issue, or a focus on other disorders were excluded. Nineteen studies were included in the systematic review. Eleven studies have stated that hypertonic saline and mannitol were equally efficacious, whereas eight studies have reported that hypertonic saline was superior. Moreover, 3% hypertonic saline was the main concentration most discussed in research. Improvements in increased intracranial pressure, cerebral perfusion pressure, survival rate, brain relaxation, and systemic hemodynamics were observed. Hypertonic saline is worthy of consideration as an excellent alternative to mannitol. This study suggests 3% hypertonic saline as the optimal concentration, with the therapeutic dose from 1.4 to 2.5 mL/kg, given as a bolus.

Propagation of tau and α-synuclein in the brain: therapeutic potential of the glymphatic system

Many neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease, are characterised by the accumulation of misfolded protein deposits in the brain, leading to a progressive destabilisation of the neuronal network and neuronal death. Among the proteins that can abnormally accumulate are tau and α-synuclein, which can propagate in a prion-like manner and which upon aggregation, represent the most common intracellular proteinaceous lesions associated with neurodegeneration. For years it was thought that these intracellular proteins and their accumulation had no immediate relationship with extracellular homeostasis pathways such as the glymphatic clearance system; however, mounting evidence has now suggested that this is not the case. The involvement of the glymphatic system in neurodegenerative disease is yet to be fully defined; however, it is becoming increasingly clear that this pathway contributes to parenchymal solute clearance. Importantly, recent data show that proteins prone to intracellular accumulation are subject to glymphatic clearance, suggesting that this system plays a key role in many neurological disorders. In this review, we provide a background on the biology of tau and α-synuclein and discuss the latest findings on the cell-to-cell propagation mechanisms of these proteins. Importantly, we discuss recent data demonstrating that manipulation of the glymphatic system may have the potential to alleviate and reduce pathogenic accumulation of propagation-prone intracellular cytotoxic proteins. Furthermore, we will allude to the latest potential therapeutic opportunities targeting the glymphatic system that might have an impact as disease modifiers in neurodegenerative diseases.

Traumatic Brain Injury-A Review of Intravenous Fluid Therapy

This manuscript will review intravenous fluid therapy in traumatic brain injury. Both human and animal literature will be included. Basic treatment recommendations will also be discussed.

What is the Role of Hyperosmolar Therapy in Hemispheric Stroke Patients?

The role of hyperosmolar therapy (HT) in large hemispheric ischemic or hemorrhagic strokes remains a controversial issue. Past and current stroke guidelines state that it represents a reasonable therapeutic measure for patients with either neurological deterioration or intracranial pressure (ICP) elevations documented by ICP monitoring. However, the lack of evidence for a clear effect of this therapy on radiological tissue shifts and clinical outcomes produces uncertainty with respect to the appropriateness of its implementation and duration in the context of radiological mass effect without clinical correlates of neurological decline or documented elevated ICP. In addition, limited data suggest a theoretical potential for harm from the prophylactic and protracted use of HT in the setting of large hemispheric lesions. HT exerts effects on parenchymal volume, cerebral blood volume and cerebral perfusion pressure which may ameliorate global ICP elevation and cerebral blood flow; nevertheless, it also holds theoretical potential for aggravating tissue shifts promoted by significant interhemispheric ICP gradients that may arise in the setting of a large unilateral supratentorial mass lesion. The purpose of this article is to review the literature in order to shed light on the effects of HT on brain tissue shifts and clinical outcome in the context of large hemispheric strokes, as well as elucidate when HT should be initiated and when it should be avoided.

Hypertonic Saline Versus Mannitol for Traumatic Brain Injury: A Systematic Review and Meta-analysis With Trial Sequential Analysis

BACKGROUND

Mannitol and hypertonic saline are widely used to treat raised intracranial pressure (ICP) after traumatic brain injury (TBI), but the clinical superiority of one over the other has not been demonstrated.

METHODS

According to the PRISMA statement, this meta-analysis reports on randomized controlled trials investigating hypertonic saline compared with mannitol in the treatment of elevated ICP following TBI. The protocol for the literature searches (Medline, Embase, Central databases), quality assessment, endpoints (mortality, favorable outcome, brain perfusion parameters), and statistical analysis plan (including a trial sequential analysis) were prospectively specified and registered on the PROSPERO database (CRD42017057112).

RESULTS

A total of 12 randomized controlled trials with 464 patients were eligible for inclusion in this analysis. Although there was a nonsignificant trend in favor of hypertonic saline, there were no significant differences in mortality between the 2 treatments (relative risk [RR]: 0.69, 95% confidence interval [CI]: 0.45, 1.04; P=0.08). There were also no significant differences in favorable neurological outcome between hypertonic saline (HS) and mannitol (RR: 1.28, 95% CI: 0.86, 1.90; P=0.23). There was no difference in ICP at 30 to 60 minutes after treatment (mean difference [MD]: -0.19 mm Hg, 95% CI: -0.54, 0.17; P=0.30), whereas ICP was significantly lower after HS compared with mannitol at 90 to 120 minutes (MD: -2.33 mm Hg, 95% CI: -3.17, -1.50; P<0.00001). Cerebral perfusion pressure was higher between 30 to 60 and 90 to 120 minutes after treatment with HS compared with after treatment with mannitol (MD: 5.48 mm Hg, 95% CI: 4.84, 6.12; P<0.00001 and 9.08 mm Hg, 95% CI: 7.54, 10.62; P<0.00001, respectively). Trial sequential analysis showed that the number of cases was insufficient to produce reliable statements on long-term outcomes.

CONCLUSION

There are indications that HS might be superior to mannitol in the treatment of TBI-related raised ICP. However, there are insufficient data to reach a definitive conclusion, and further studies are warranted.

Tuberculosis in Intensive Care Unit

About 3.4% of the hospitalized tubercular patients need admission to the intensive care unit (ICU). Patients requiring ICU admission had a poor prognosis and high mortality rate (60 vs 25%) as compared to other causes of severe pneumonia. The most common indication for tuberculosis-related ICU admission is acute respiratory failure due to pneumonia or acute respiratory distress syndrome (ARDS) (with or without miliary tuberculosis) followed by septic shock with multiple organ dysfunction, adrenal insufficiency, and neurological involvement, especially tubercular meningitis. Tuberculosis patients who require admission to ICU are mostly immunocompromised [human immunodeficiency virus (HIV) coinfection] and have underlying miliary tuberculosis or disseminated tuberculosis. Pulmonary tuberculosis presenting as ARDS is a rare phenomenon, but a most common cause of admission of tuberculosis patients to ICU. Tuberculous meningitis is the most severe form of tuberculosis with mortality more than 60% and residual neurological disability in 25% cases. Tuberculosis-related septic shock has been found in only 1% of all septic shock patients admitted to ICU. Patients with tuberculosis with refractory shock should be suspected for adrenal insufficiency. A trial of physiologic stress replacement dose of hydrocortisone (200–300 mg) should be given to all critically ill patients with vasopressor-dependent shock after correcting other causes. Diagnosis and treatment of tuberculosis in critically ill patients has various challenges, namely appropriate sample collection, issues with the route of administration, drug absorption, bioavailability, dose modification in hepatic and renal dysfunction, and interaction with other drugs.

How to cite this article: Chaudhry D, Tyagi D. Tuberculosis in Intensive Care Unit. Indian J Crit Care Med 2021;25(Suppl 2):S150–S154.

Multiple trauma management in mountain environments - a scoping review : Evidence based guidelines of the International Commission for Mountain Emergency Medicine (ICAR MedCom). Intended for physicians and other advanced life support personnel

Background

Multiple trauma in mountain environments may be associated with increased morbidity and mortality compared to urban environments.

Objective

To provide evidence based guidance to assist rescuers in multiple trauma management in mountain environments.

Eligibility criteria

All articles published on or before September 30th 2019, in all languages, were included. Articles were searched with predefined search terms.

Sources of evidence

PubMed, Cochrane Database of Systematic Reviews and hand searching of relevant studies from the reference list of included articles.

Charting methods

Evidence was searched according to clinically relevant topics and PICO questions.

Results

Two-hundred forty-seven articles met the inclusion criteria. Recommendations were developed and graded according to the evidence-grading system of the American College of Chest Physicians. The manuscript was initially written and discussed by the coauthors. Then it was presented to ICAR MedCom in draft and again in final form for discussion and internal peer review. Finally, in a face-to-face discussion within ICAR MedCom consensus was reached on October 11th 2019, at the ICAR fall meeting in Zakopane, Poland.

Conclusions

Multiple trauma management in mountain environments can be demanding. Safety of the rescuers and the victim has priority. A crABCDE approach, with haemorrhage control first, is central, followed by basic first aid, splinting, immobilisation, analgesia, and insulation. Time for on-site medical treatment must be balanced against the need for rapid transfer to a trauma centre and should be as short as possible. Reduced on-scene times may be achieved with helicopter rescue. Advanced diagnostics (e.g. ultrasound) may be used and treatment continued during transport.

Hypertonic saline and mannitol in patients with traumatic brain injury: A systematic and meta-analysis

BACKGROUND

To compare the effects of 3% hypertonic saline solution and 20% mannitol solution on intracranial hypertension.

METHODS

WAN-FANGDATA, CNKI, and CQVIP databases were searched, and relevant literatures of randomized controlled trials comparing 3% hypertonic saline solution with mannitol in reducing intracranial hypertension from 2010 to October 2019 were collected. Meta-analysis was performed using RevMan software.

RESULTS

As a result, 10 articles that met the inclusion criteria were finally included. A total of 544 patients were enrolled in the study, 270 in the hypertonic saline group and 274 in the mannitol group. There was no significant difference in the decrease of intracranial pressure and the onset time of drug between the 2 groups after intervention (all P > .05). There was a statistically significant difference between the hypertonic saline group and the mannitol group in terms of duration of effect in reducing intracranial pressure (95% confidence interval: 0.64-1.05, Z = 8.09, P < .00001) and cerebral perfusion pressure after intervention (95% confidence interval: 0.15-0.92, Z = 2.72, P = .007).

CONCLUSION

Both 3% hypertonic saline and mannitol can effectively reduce intracranial pressure, but 3% hypertonic saline has a more sustained effect on intracranial pressure and can effectively increase cerebral perfusion pressure.

Intraosseous Administration of Hypertonic Saline in Acute Brain-Injured Patients: A Prospective Case Series and Literature Review

BACKGROUND

Central venous catheters are often used to administer hypertonic saline (HTS) but might be associated with serious complications. Intraosseous (IO) access is an alternative method of medication and fluid delivery which is not associated with life-threatening complications and can be inserted faster than CVCs.

METHODS

A prospective case series was conducted on critically ill neurological patients that did not have central venous access, and for whom 3% HTS was indicated. Nonverbal indicators of pain were measured using the critical care pain observation tool. The pain score and serum sodium levels were collected at baseline, at 2, 6, 12, 18, and 24 hours after administration of 3% HTS using IO access. The area surrounding the IO insertion site was monitored for needle placement, extravasation, and tissue damage.

RESULTS

Five patients were enrolled. Three had an IO placed in the proximal humerus and 2 in the proximal tibia. Most patients did not have nonverbal indicators of pain during insertion and initial bolus. Serum sodium levels increased appropriately, as determined by the care providers. There were no cases of device dislodgement, extravasation, infection, soft tissue injury, or other local complications.

CONCLUSIONS

In this prospective case series, IO administration of 3% HTS was feasible, well-tolerated on the basis of nonverbal indicators of pain in the majority of patients and resulted in an appropriate rise in serum sodium levels. IO fills a niche among vascular access options for HTS, in emergent neurological situations when central venous access is not readily available or peripheral intravenous access is difficult to obtain.

Hyperosmolar therapy for acute brain injury: study protocol for an umbrella review of meta-analyses and an evidence mapping

INTRODUCTION

Acute brain injury is a challenging public health problem worldwide. Elevated intracranial pressure is a common complication after acute brain injury. Hyperosmolar therapy is one of the main therapeutic strategies for the management of intracranial hypertension. This study protocol outlines an umbrella review of meta-analyses which will investigate the benefits and harms of hyperosmolar therapy routinely used for the management of acute brain injury in the intensive care.

METHODS AND ANALYSIS

We will search PubMed/MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews. We will include meta-analyses of primary research studies (eg, randomised controlled trials, observational studies or both) that evaluate one or more hyperosmolar solutions (including hypertonic saline and/or mannitol) for the treatment of adult patients with acute brain injury of any severity. Two researchers will independently screen all citations, full-text articles and abstract data. Potential conflicts will be resolved through discussion with a third researcher. Primary outcomes will be mortality and neurological outcomes at discharge. Secondary outcomes will include control of intracranial pressure, cerebral perfusion pressure, length of stay (in hospital an intensive care unit) and any adverse event. Quality of the included meta-analyses will be assessed using the AMSTAR-2 tool. An overall summary of methods and results will be performed using tabular and graphical approaches and will be supplemented by narrative description. We will analyse whether published meta-analyses present an outline of available evidence (eg, cited, described and discussed any previous meta-analysis). Where objectives from two or more meta-analyses overlap, we will assess the causes of any noted discrepancies between meta-analyses.

ETHICS AND DISSEMINATION

No ethical approval will be required. Findings from this study will be published in a peer-reviewed journal. All data will be deposited in a cross-disciplinary public repository.

PROSPERO REGISTRATION NUMBER

CRD42019148152.

Hypertonic saline versus other intracranial pressure-lowering agents for people with acute traumatic brain injury

BACKGROUND

Increased intracranial pressure has been shown to be strongly associated with poor neurological outcomes and mortality for patients with acute traumatic brain injury. Currently, most efforts to treat these injuries focus on controlling the intracranial pressure. Hypertonic saline is a hyperosmolar therapy that is used in traumatic brain injury to reduce intracranial pressure. The effectiveness of hypertonic saline compared with other intracranial pressure-lowering agents in the management of acute traumatic brain injury is still debated, both in the short and the long term.

OBJECTIVES

To assess the comparative efficacy and safety of hypertonic saline versus other intracranial pressure-lowering agents in the management of acute traumatic brain injury.

SEARCH METHODS

We searched Cochrane Injuries' Specialised Register, CENTRAL, PubMed, Embase Classic+Embase, ISI Web of Science: Science Citation Index and Conference Proceedings Citation Index-Science, as well as trials registers, on 11 December 2019. We supplemented these searches with searches of four major Chinese databases on 19 September 2018. We also checked bibliographies, and contacted trial authors to identify additional trials.

SELECTION CRITERIA

We sought to identify all randomised controlled trials (RCTs) of hypertonic saline versus other intracranial pressure-lowering agents for people with acute traumatic brain injury of any severity. We excluded cross-over trials as incompatible with assessing long-term outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results to identify potentially eligible trials and extracted data using a standard data extraction form. Outcome measures included: mortality at end of follow-up (all-cause); death or disability (as measured by the Glasgow Outcome Scale (GOS)); uncontrolled intracranial pressure (defined as failure to decrease the intracranial pressure to target and/or requiring additional intervention); and adverse events e.g. rebound phenomena; pulmonary oedema; acute renal failure during treatment).

MAIN RESULTS

Six trials, involving data from 287 people, met the inclusion criteria. The majority of participants (91%) had a diagnosis of severe traumatic brain injury. We had concerns about particular domains of risk of bias in each trial, as physicians were not reliably blinded to allocation, two trials contained participants with conditions other than traumatic brain injury and in one trial, we had concerns about missing data for important outcomes. The original protocol was available for only one trial and other trials (where registered) were registered retrospectively. Meta-analysis for both the primary outcome (mortality at final follow-up) and for 'poor outcome' as per conventionally dichotomised GOS criteria, was only possible for two trials. Synthesis of long-term outcomes was inhibited by the fact that two trials ceased data collection within two hours of a single bolus dose of an intracranial pressure-lowering agent and one at discharge from the intensive care unit (ICU). Only three trials collected data after participants were released from hospital, one of which did not report mortality and reported a 'poor outcome' by GOS criteria in an unconventional way. Substantial missing data in a key trial meant that in meta-analysis we report 'best-case' and 'worst-case' estimates alongside available case analysis. In no scenario did we discern a clear difference between treatments for either mortality or poor neurological outcome. Due to variation in modes of drug administration (including whether it followed or did not follow cerebrospinal fluid (CSF) drainage, as well as different follow-up times and ways of reporting changes in intracranial pressure, as well as no uniform definition of 'uncontrolled intracranial pressure', we did not perform meta-analysis for this outcome and report results narratively, by individual trial. Trials tended to report both treatments to be effective in reducing elevated intracranial pressure but that hypertonic saline had increased benefits, usually adding that pretreatment factors need to be considered (e.g. serum sodium and both system and brain haemodynamics). No trial provided data for our other outcomes of interest. We consider evidence quality for all outcomes to be very low, as assessed by GRADE; we downgraded all conclusions due to imprecision (small sample size), indirectness (due to choice of measurement and/or selection of participants without traumatic brain injury), and in some cases, risk of bias and inconsistency. Only one of the included trials reported data on adverse effects; a rebound phenomenon, which was present only in the comparator group (mannitol). None of the trials reported data on pulmonary oedema or acute renal failure during treatment. On the whole, trial authors do not seem to have rigorously sought to collect data on adverse events.

AUTHORS' CONCLUSIONS

This review set out to find trials comparing hypertonic saline to a potential range of other intracranial pressure-lowering agents, but only identified trials comparing it with mannitol or mannitol in combination with glycerol. Based on limited data, there is weak evidence to suggest that hypertonic saline is no better than mannitol in efficacy and safety in the long-term management of acute traumatic brain injury. Future research should be comprised of large, multi-site trials, prospectively registered, reported in accordance with current best practice. Trials should investigate issues such as the type of traumatic brain injury suffered by participants and concentration of infusion and length of time over which the infusion is given.

Hypertonic saline versus other intracranial pressure-lowering agents for people with acute traumatic brain injury

BACKGROUND

Increased intracranial pressure (ICP) has been shown to be strongly associated with poor neurological outcomes and mortality for patients with acute traumatic brain injury (TBI). Currently, most efforts to treat these injuries focus on controlling the ICP. Hypertonic saline (HTS) is a hyperosmolar therapy that is used in traumatic brain injury to reduce intracranial pressure. The effectiveness of HTS compared with other ICP-lowering agents in the management of acute TBI is still debated, both in the short and the long term.

OBJECTIVES

To assess the comparative efficacy and safety of hypertonic saline versus other ICP-lowering agents in the management of acute TBI.

SEARCH METHODS

We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, PubMed, Embase Classic+Embase (OvidSP), ISI Web of Science: Science Citation Index and Conference Proceedings Citation Index-Science, as well as trials registers, on 11 December 2019. We supplemented these searches using four major Chinese databases on 19 September 2018. We also checked bibliographies, and contacted study authors to identify additional studies.

SELECTION CRITERIA

We sought to identify all randomised controlled trials (RCTs) of HTS versus other intracranial pressure-lowering agents for people with acute TBI of any severity. We excluded cross-over trials as incompatible with assessing long term outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results to identify potentially eligible trials and extracted data using a standard data extraction form. Outcome measures included: mortality at end of follow-up (all-cause); death or disability (as measured by the Glasgow Outcome Scale (GOS)); uncontrolled ICP (defined as failure to decrease the ICP to target and/or requiring additional intervention); and adverse events (AEs) (e.g. rebound phenomena; pulmonary oedema; acute renal failure during treatment).

MAIN RESULTS

Six trials, involving data from 295 people, met the inclusion criteria. The majority of participants (89%) had a diagnosis of severe TBI. We had concerns about particular domains of risk of bias in each trial, as physicians were not reliably blinded to allocation, two trials contained participants with conditions other than TBI and in one trial, there were concerns about missing data for important outcomes. The original protocol was available for only one study and other trials (where registered) were registered retrospectively. Meta-analysis for both the primary outcome (mortality at final follow up) and for 'poor outcome' as per conventionally dichotomised GOS criteria, was only possible for two studies. Synthesis of long-term outcomes was inhibited by the fact that two ceased data collection within two hours of a single bolus dose of an ICP-lowering agent and one at discharge from ICU. Only three studies collected data after release from hospital. Due to variation in modes of drug administration, follow-up times, and ways of reporting changes in ICP, as well as no uniform definition of 'uncontrolled ICP', we did not perform meta-analysis for this outcome and report results narratively, by individual trial. Trials tended to report both treatments to be effective in reducing elevated ICP but that HTS had increased benefits, usually adding that pretreatment factors need to be considered (e.g. serum sodium and both system and brain hemodynamics). No trial provided data for our other outcomes of interest. Evidence for all outcomes is considered very low, as assessed by GRADE. All conclusions were downgraded due to imprecision (small sample size), indirectness (due to choice of measurement and/or selection of patients without TBI), and in some cases, risk of bias and inconsistency. Only one of the included trials reported data on adverse effects (AEs) - a rebound phenomenon, which was present only in the comparator group (mannitol). No data were reported on pulmonary oedema or acute renal failure during treatment. On the whole, investigators do not seem to have rigorously sought to collect data on AEs.

AUTHORS' CONCLUSIONS

This review set out to find trials comparing HTS to a potential range of other ICP-lowering agents, but only identified trials comparing it with mannitol or mannitol in combination with glycerol. Based on limited data, there is weak evidence to suggest that HTS is no better than mannitol in efficacy and safety in the long-term management of acute TBI. Future research should be comprised of large, multi-site trials, prospectively registered, reported in accordance with current best practice. Issues such as the type of TBI suffered by participants and concentration of infusion and length of time over which the infusion is given should be investigated.

Hypertonic saline versus mannitol for the treatment of increased intracranial pressure in traumatic brain injury

BACKGROUND

Increased intracranial pressure (ICP) occurring after traumatic brain injury (TBI) is associated with increased morbidity and mortality. If appropriate treatments are not initiated, brain herniation can occur and lead to death. Previously, the Brain Trauma Foundation recommended mannitol as the first-choice hyperosmolar agent. However, in 2016, they retracted this recommendation, citing a lack of sufficient supporting evidence. Current research shows that hypertonic saline (HTS) also decreases ICP.

OBJECTIVES

To compare the efficacy of HTS and mannitol in lowering ICP in patients with TBI.

DATA SOURCES

A search was conducted up to June 1, 2019, using PubMed, Embase, CINAHL, and Web of Science. Selected articles compared mannitol and HTS in adults with TBI, with the measured outcome of reduced ICP. Four meta-analyses, three randomized controlled trials, and one retrospective cohort study met the inclusion criteria.

CONCLUSIONS

Hypertonic saline is an effective alternative to mannitol for increased ICP. Three studies suggested HTS may be superior to mannitol. Conclusions were limited by sample size and methodological differences, such as varying concentrations and doses, and inclusion of patients without TBI in their studies.

IMPLICATIONS FOR PRACTICE

Evidence demonstrates HTS to be as effective as mannitol for ICP reduction. Further research in a large multicenter clinical trial is needed to compare these two agents for superiority in the management of increased ICP. Providers should consider the properties of each agent, adverse effects, and potential benefits when selecting a hyperosmotic agent.

Hypertonic saline or mannitol for treating elevated intracranial pressure in traumatic brain injury: a meta-analysis of randomized controlled trials

Hyperosmolar therapy is regarded as the mainstay for treatment of elevated intracranial pressure (ICP) in traumatic brain injury (TBI). This still has been disputed as application of hypertonic saline (HS) or mannitol for treating patients with severe TBI. Thus, this meta-analysis was performed to further compare the advantages and disadvantages of mannitol with HS for treating elevated ICP after TBI. We conducted a systematic search on PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Wan Fang Data, VIP Data, SinoMed, and China National Knowledge Infrastructure (CNKI) databases. Studies were included or not based on the quality assessment by the Jadad scale and selection criteria. Twelve RCTs with 438 patients were enrolled for the meta-analysis. The comparison of HS and mannitol indicated that they were close in field of improving function outcome (RR = 1.17, 95% CI 0.89 to 1.54, p = 0.258) and reducing intracranial pressure (MD = - 0.16, 95% CI: - 0.59 to 0.27, p = 0.473) and mortality (RR = 0.78, 95% CI 0.53 to 1.16, p = 0.216). The pooled relative risk of successful ICP control was 1.06 (95% CI: 1.00 to 1.13, p = 0.044), demonstrating that HS was more effective than mannitol in ICP management. Both serum sodium (WMD = 5.30, 95% CI: 4.37 to 6.22, p < 0.001) and osmolality (WMD = 3.03, 95% CI: 0.18 to 5.88, p = 0.037) were increased after injection of hypertonic saline. The results do not lend a specific recommendation to select hypertonic saline or mannitol as a first-line for the patients with elevated ICP caused by TBI. However, for the refractory intracranial hypertension, hypertonic saline seems to be preferred.

Contemporary Management of Increased Intraoperative Intracranial Pressure: Evidence-Based Anesthetic and Surgical Review

Increased intracranial pressure (ICP) is frequently encountered in the neurosurgical setting. A multitude of tactics exists to reduce ICP, ranging from patient position and medications to cerebrospinal fluid diversion and surgical decompression. A vast amount of literature has been published regarding ICP management in the critical care setting, but studies specifically tailored toward the management of intraoperative acute increases in ICP or brain bulk are lacking. Compartmentalizing the intracranial space into blood, brain tissue, and cerebrospinal fluid and understanding the numerous techniques available to affect these individual compartments can guide the surgical team to quickly identify increased brain bulk and respond appropriately. Rapidly instituting measures for brain relaxation in the operating room is essential in optimizing patient outcomes. Knowledge of the efficacy, rapidity, feasibility, and risks of the various available interventions can aid the team to properly tailor their approach to each individual patient. In this article, we present the first evidence-based review of intraoperative management of ICP and brain bulk.

The neurocritical care of tuberculous meningitis

Tuberculous meningitis is the most severe form of tuberculosis and often causes critical illness with high mortality. Two primary management objectives are reducing intracranial pressure, and optimising cerebral perfusion, while killing the bacteria and controlling intracerebral inflammation. However, the evidence base guiding the care of critically ill patients with tuberculous meningitis is poor and many patients do not have access to neurocritical care units. Invasive intracranial pressure monitoring is often unavailable and although new non-invasive monitoring techniques show promise, further evidence for their use is required. Optimal management regimens of neurological complications (eg, hydrocephalus and paradoxical reactions) and of hyponatraemia, which frequently accompanies tuberculous meningitis, remain to be elucidated. Advances in the field of tuberculous meningitis predominantly focus on diagnosis, inflammatory processes, and antituberculosis chemotherapy. However, clinical trials are required to provide robust evidence guiding the most effective supportive, therapeutic, and neurosurgical interventions for tuberculous meningitis that will improve morbidity and mortality.

Management of Traumatic Brain Injury: An Update

The care of patients with traumatic brain injury can be one of the most challenging and rewarding aspects of clinical neurocritical care. This article reviews the approach to unique aspects specific to the care of this patient population. These aspects include appropriate use of sedation and analgesia, and the principles and the clinical use of intracranial monitors. Common clinical challenges encountered in these patients are also discussed, including the treatment of intracranial hypertension, temperature management, and control of sympathetic hyperactivity.

Pathophysiology and Management of Intracranial Hypertension and Tissular Brain Hypoxia After Severe Traumatic Brain Injury: An Integrative Approach

Monitoring intracranial pressure in comatose patients with severe traumatic brain injury (TBI) is considered necessary by most experts. Acute intracranial hypertension (IHT), when severe and sustained, is a life-threatening complication that demands emergency treatment. Yet, secondary anoxic-ischemic injury after brain trauma can occur in the absence of IHT. In such cases, adding other monitoring modalities can alert clinicians when the patient is in a state of energy failure. This article reviews the mechanisms, diagnosis, and treatment of IHT and brain hypoxia after TBI, emphasizing the need to develop a physiologically integrative approach to the management of these complex situations.

The currency, completeness and quality of systematic reviews of acute management of moderate to severe traumatic brain injury: A comprehensive evidence map

OBJECTIVE

To appraise the currency, completeness and quality of evidence from systematic reviews (SRs) of acute management of moderate to severe traumatic brain injury (TBI).

METHODS

We conducted comprehensive searches to March 2016 for published, English-language SRs and RCTs of acute management of moderate to severe TBI. Systematic reviews and RCTs were grouped under 12 broad intervention categories. For each review, we mapped the included and non-included RCTs, noting the reasons why RCTs were omitted. An SR was judged as 'current' when it included the most recently published RCT we found on their topic, and 'complete' when it included every RCT we found that met its inclusion criteria, taking account of when the review was conducted. Quality was assessed using the AMSTAR checklist (trichotomised into low, moderate and high quality).

FINDINGS

We included 85 SRs and 213 RCTs examining the effectiveness of treatments for acute management of moderate to severe TBI. The most frequently reviewed interventions were hypothermia (n = 17, 14.2%), hypertonic saline and/or mannitol (n = 9, 7.5%) and surgery (n = 8, 6.7%). Of the 80 single-intervention SRs, approximately half (n = 44, 55%) were judged as current and two-thirds (n = 52, 65.0%) as complete. When considering only the most recently published review on each intervention (n = 25), currency increased to 72.0% (n = 18). Less than half of the 85 SRs were judged as high quality (n = 38, 44.7%), and nearly 20% were low quality (n = 16, 18.8%). Only 16 (20.0%) of the single-intervention reviews (and none of the five multi-intervention reviews) were judged as current, complete and high-quality. These included reviews of red blood cell transfusion, hypothermia, management guided by intracranial pressure, pharmacological agents (various) and prehospital intubation. Over three-quarters (n = 167, 78.4%) of the 213 RCTs were included in one or more SR. Of the remainder, 17 (8.0%) RCTs post-dated or were out of scope of existing SRs, and 29 (13.6%) were on interventions that have not been assessed in SRs.

CONCLUSION

A substantial number of SRs in acute management of moderate to severe TBI lack currency, completeness and quality. We have identified both potential evidence gaps and also substantial research waste. Novel review methods, such as Living Systematic Reviews, may ameliorate these shortcomings and enhance utility and reliability of the evidence underpinning clinical care.

Pediatric Major Head Injury: Not a Minor Problem

Traumatic brain injury is a highly prevalent and devastating cause of morbidity and mortality in children. A rapid, stepwise approach to the traumatized child should proceed, addressing life-threatening problems first. Management focuses on preventing secondary injury from physiologic extremes such as hypoxemia, hypotension, prolonged hyperventilation, temperature extremes, and rapid changes in cerebral blood flow. Initial Glasgow Coma Score, hyperglycemia, and imaging are often prognostic of outcome. Surgically amenable lesions should be evacuated promptly. Reduction of intracranial pressure through hyperosmolar therapy, decompressive craniotomy, and seizure prophylaxis may be considered after stabilization. Nonaccidental trauma should be considered when evaluating pediatric trauma patients.

Italian guidelines on the assessment and management of pediatric head injury in the emergency department

OBJECTIVE

We aim to formulate evidence-based recommendations to assist physicians decision-making in the assessment and management of children younger than 16 years presenting to the emergency department (ED) following a blunt head trauma with no suspicion of non-accidental injury.

METHODS

These guidelines were commissioned by the Italian Society of Pediatric Emergency Medicine and include a systematic review and analysis of the literature published since 2005. Physicians with expertise and experience in the fields of pediatrics, pediatric emergency medicine, pediatric intensive care, neurosurgery and neuroradiology, as well as an experienced pediatric nurse and a parent representative were the components of the guidelines working group. Areas of direct interest included 1) initial assessment and stabilization in the ED, 2) diagnosis of clinically important traumatic brain injury in the ED, 3) management and disposition in the ED. The guidelines do not provide specific guidance on the identification and management of possible associated cervical spine injuries. Other exclusions are noted in the full text.

CONCLUSIONS

Recommendations to guide physicians practice when assessing children presenting to the ED following blunt head trauma are reported in both summary and extensive format in the guideline document.

Raised intracranial pressure and brain edema

Acutely increased intracranial pressure (ICP) is a life-threatening neurosurgical emergency. Optimal management strategy is selected according to the causative process. Typical causes are intracranial bleeds like traumatic subdural, epidural, or intracerebral hematoma (ICH); spontaneous ICH, intraventricular hemorrhage, subarachnoid hemorrhage, and hydrocephalus. When occurring without significant brain injury and treated effectively before herniation, a full recovery can be expected. In intraparenchymal injuries a full recovery is unlikely since dead cells in the central nervous system leave an "empty hole," to be replaced by cerebrospinal fluid. The clinical recovery is based on the surviving cells that are able to make new synapses. Surgery may decrease ICP by removing significant mass effect. In all conditions, when notable injury of brain parenchyma occurs, brain edema may gradually increase ICP and further worsen the clinical condition. This is seen typically in large brain infarctions when the formation of brain edema may lead to increased ICP for hours and days. Brain edema is traditionally classified as vasogenic or cytotoxic but according to current knowledge is rather a continuum, starting with cytotoxic cell swelling followed by ionic edema and then vasogenic edema. Here we review the causes of increased ICP, including mechanisms of brain edema, with clinical examples.

Management of severe traumatic brain injury (first 24hours)

The latest French Guidelines for the management in the first 24hours of patients with severe traumatic brain injury (TBI) were published in 1998. Due to recent changes (intracerebral monitoring, cerebral perfusion pressure management, treatment of raised intracranial pressure), an update was required. Our objective has been to specify the significant developments since 1998. These guidelines were conducted by a group of experts for the French Society of Anesthesia and Intensive Care Medicine (Société francaise d'anesthésie et de réanimation [SFAR]) in partnership with the Association de neuro-anesthésie-réanimation de langue française (ANARLF), The French Society of Emergency Medicine (Société française de médecine d'urgence (SFMU), the Société française de neurochirurgie (SFN), the Groupe francophone de réanimation et d'urgences pédiatriques (GFRUP) and the Association des anesthésistes-réanimateurs pédiatriques d'expression française (ADARPEF). The method used to elaborate these guidelines was the Grade^® method. After two Delphi rounds, 32 recommendations were formally developed by the experts focusing on the evaluation the initial severity of traumatic brain injury, the modalities of prehospital management, imaging strategies, indications for neurosurgical interventions, sedation and analgesia, indications and modalities of cerebral monitoring, medical management of raised intracranial pressure, management of multiple trauma with severe traumatic brain injury, detection and prevention of post-traumatic epilepsia, biological homeostasis (osmolarity, glycaemia, adrenal axis) and paediatric specificities.

Management of Traumatic Brain Injury: An Update

The care of patients with traumatic brain injury can be one of the most challenging and rewarding aspects of clinical neurocritical care. This article reviews the approach to unique aspects specific to the care of this patient population. These aspects include appropriate use of sedation and analgesia, and the principles and the clinical use of intracranial monitors. Common clinical challenges encountered in these patients are also discussed, including the treatment of intracranial hypertension, temperature management, and control of sympathetic hyperactivity.

Comparison of the effects of 7.2% hypertonic saline and 20% mannitol on whole blood coagulation and platelet function in dogs with suspected intracranial hypertension - a pilot study

BACKGROUND

Hyperosmolar therapy with either mannitol or hypertonic saline (HTS) is commonly used in the treatment of intracranial hypertension (ICH). In vitro data indicate that both mannitol and HTS affect coagulation and platelet function in dogs. The aim of this study was to compare the effects of 20% mannitol and 7.2% HTS on whole blood coagulation using rotational thromboelastometry (ROTEM®) and platelet function using a platelet function analyzer (PFA®) in dogs with suspected ICH. Thirty client-owned dogs with suspected ICH needing osmotherapy were randomized to receive either 20% mannitol (5 ml/kg IV over 15 min) or 7.2% HTS (4 ml/kg IV over 5 min). ROTEM® (EXTEM® and FIBTEM® assays) and PFA® analyses (collagen/ADP cartridges) were performed before (T0), as well as 5 (T5), 60 (T60) and 120 (T120) minutes after administration of HTS or mannitol. Data at T5, T60 and T120 were analyzed as a percentage of values at T0 for comparison between groups, and as absolute values for comparison between time points, respectively.

RESULTS

No significant difference was found between the groups for the percentage change of any parameter at any time point except for FIBTEM® clotting time. Within each group, no significant difference was found between time points for any parameter except for FIBTEM® clotting time in the HTS group, and EXTEM® and FIBTEM® maximum clot firmness in the mannitol group. Median ROTEM® values lay within institutional reference intervals in both groups at all time points, whereas median PFA® values were above the reference intervals at T5 (both groups) and T60 (HTS group).

CONCLUSIONS

Using currently recommended doses, mannitol and HTS do not differ in their effects on whole blood coagulation and platelet function in dogs with suspected ICH. Moreover, no relevant impairment of whole blood coagulation was found following treatment with either solution, whereas a short-lived impairment of platelet function was found after both solutions.

[Neuroanesthesia]

Anesthesiological challenges during craniotomy result from the anatomically related low compensatory capacity of the intracranial space in response to increased volume and the low ischemic tolerance of brain tissue. The anesthetic agents used should therefore not increase the intracranial volume and improve the ischemic tolerance. An acute life-threatening increase of intracranial pressure can be temporarily treated by hyperventilation until measures, such as osmotherapy and infusion of intravenous anesthetics become effective. During an operation the homeostatic parameters including blood volume, blood pressure, partial pressure of carbon dioxide and oxygen in blood, plasma glucose concentration and core body temperature have to be closely monitored and kept normal (6 Ns). Optimal implementation of anesthesia necessitates a detailed knowledge of the surgical approach and potential complications. Postoperatively, patients should be extubated as soon as possible to closely monitor cognitive function so that potential deterioration can be detected.

Hyperosmolar therapy in pediatric traumatic brain injury: a retrospective study

OBJECTIVES

The objectives of the study are to describe the use of hyperosmolar therapy in pediatric traumatic brain injury (TBI) and examine its effect on intracranial pressure (ICP) and cerebral perfusion pressure (CPP).

DESIGN

A retrospective review of patients with severe TBI admitted to the pediatric intensive care unit (PICU) was conducted. Inclusion criteria were ICP monitoring and administration of a hyperosmolar agent (20 % mannitol or 3 % hypertonic saline) within 48 h of PICU admission; for which dose and timing were recorded. For the first two boluses received for increased ICP (>20 mmHg), the impact on ICP and CPP was assessed during the following 4 h, using repeated measures ANOVA. Co-interventions to control ICP (additional hyperosmolar agent, propofol, or barbiturate bolus) and serum sodium were also documented.

SETTING

A tertiary care pediatric hospital center.

PATIENTS

Children aged 1 month to 18 years, with severe traumatic brain injury (Glasgow Coma Score ≤ 8) and intracranial pressure (ICP) monitor.

RESULTS

Sixty-four patients were eligible, of which 16 met inclusion criteria. Average age was 11 years (SD ± 4) and median Glasgow Coma Score was 6 (range 4-7). Seventy percent of boluses were 3 % hypertonic saline, with no identified baseline difference associated with this initial choice. Both mannitol and hypertonic saline were followed by a non-significant decrease in ICP (mannitol, p = 0.055 and hypertonic saline, p = 0.096). There was no significant change in CPP post bolus. A co-intervention occurred in 69 % of patients within the 4 h post hyperosmolar agent, and eight patients received continuous 3 % saline.

CONCLUSION

In pediatric TBI with intracranial hypertension, mannitol and 3 % hypertonic saline are commonly used, but dose and therapeutic threshold for use vary without clear indications for one versus another. Controlled trials are warranted, but several barriers were identified, including high exclusion rate, multiple co-interventions, and care variability.

SGEM Hot Off the Press: hypertonic saline in severe traumatic brain injury: a systematic review and meta-analysis of randomized controlled trials

As part of the Canadian Journal of Emergency Medicine’s (CJEM) developing social media strategy,1 we are collaborating with the Skeptics’ Guide to Emergency Medicine (SGEM) to summarize and critically appraise the current emergency medicine (EM) literature using evidence-based medicine principles. In the “Hot Off the Press” series, we select original research manuscripts published in CJEM to be featured on the SGEM website/podcast and discussed by the study authors and the online EM community. A similar collaboration is under way between the SGEM and Academic Emergency Medicine. What follows is a summary of the selected article, the immediate post-publication synthesis from the SGEM podcast, commentary by the first author, and the subsequent discussion from the SGEM blog and other social media. Through this series, we hope to enhance the value, accessibility, and application of important, clinically relevant EM research. In this, the second SGEM HOP hosted collaboratively with CJEM, we discuss a systematic review evaluating the use of hypertonic saline in the treatment of severe traumatic brain injury.2

Traumatic brain injury: physiological targets for clinical practice in the prehospital setting and on the Neuro-ICU

PURPOSE OF REVIEW

Over many years, understanding of the pathophysiology in traumatic brain injury (TBI) has resulted in the development of core physiological targets and therapies to preserve cerebral oxygenation, and in doing so prevent secondary insult. The present review revisits the evidence for these targets and therapies.

RECENT FINDINGS

Achieving oxygen, carbon dioxide, blood pressure, temperature and glucose targets remain a key goal of therapy in TBI, as does the role of effective prehospital care. Physician led air ambulance teams reduce mortality. Normobaric hyperoxia is dangerous to the injured brain; as are both high and low carbon dioxide levels. Hypotension is life threatening and higher targets have now been suggested in TBI. Both therapeutic normothermia and hypothermia have a role in specific groups of patients with TBI. Although consensus has not been reached on the optimal intravenous fluid for resuscitation in TBI, vigilant goal-directed fluid administration may improve outcome. Osmotherapeutic agents such as hypertonic sodium lactate solutions may also have a role alongside conventional agents.

SUMMARY

Maintaining physiological targets in several areas remains part of protocol led care in the acute phase of TBI management. As evidence accumulates however, the target values and therefore therapies may be set to change.

Hypertonic saline in severe traumatic brain injury: a systematic review and meta-analysis of randomized controlled trials

Objectives

Hypertonic saline solutions are increasingly used to treat increased intracranial pressure following severe traumatic brain injury. However, whether hypertonic saline provides superior management of intracranial pressure and improves outcome is unclear. We thus conducted a systematic review to evaluate the effect of hypertonic saline in patients with severe traumatic brain injury.

Methods

Two researchers independently selected randomized controlled trials studying hypertonic saline in severe traumatic brain injury and collected data using a standardized abstraction form. No language restriction was applied. We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and BIOSIS databases. We searched grey literature via OpenGrey and National Technical Information Service databases. We searched the references of included studies and relevant reviews for additional studies.

Results

Eleven studies (1,820 patients) were included. Hypertonic saline did not decrease mortality (risk ratio 0.96, 95% confidence interval [CI] 0.83 to 1.11, I2=0%) or improve intracranial pressure control (weighted mean difference −1.25 mm Hg, 95% CI −4.18 to 1.68, I2=78%) as compared to any other solutions. Only one study reported monitoring for adverse events with hypertonic saline, finding no significant differences between comparison groups.

Conclusions

We observed no mortality benefit or effect on the control of intracranial pressure with the use of hypertonic saline when compared to other solutions. Based on the current level of evidence pertaining to mortality or control of intracranial pressure, hypertonic saline could thus not be recommended as a first-line agent for managing patients with severe traumatic brain injury.

A Systematic Review of Randomized Controlled Trials Comparing Hypertonic Sodium Solutions and Mannitol for Traumatic Brain Injury

Objective: To comparatively evaluate hypertonic sodium (HTS) and mannitol in patients following acute traumatic brain injury (TBI) on the outcomes of all-cause mortality, neurological disability, intracranial pressure (ICP) change from baseline, ICP treatment failure, and serious adverse events. Data Sources: PubMed, EMBASE, CENTRAL, Cochrane Database of Systematic Reviews, ClinicalTrials.gov, and WHO ICTRP (World Health Organization International Clinical Trials Registry Platform) were searched (inception to November 2015) using hypertonic saline solutions, sodium chloride, mannitol, osmotic diuretic, traumatic brain injury, brain injuries, and head injury. Searches were limited to humans. Clinical practice guidelines and bibliographies were reviewed. Study Selection and Data Extraction: Prospective, randomized trials comparing HTS and mannitol in adults (≥16 years) with severe TBI (Glasgow Coma Scale score ≤8) and elevated ICP were included. ICP elevation, ICP reduction, and treatment failure were defined using study definitions. Data Synthesis: Of 326 articles screened, 7 trials enrolling a total of 191 patients met inclusion criteria. Studies were underpowered to detect a significant difference in mortality or neurological outcomes. Due to significant heterogeneity and differences in reporting ICP change from baseline, this outcome was not meta-analyzed. No difference between HTS and mannitol was observed for mean ICP reduction; however, risk of ICP treatment failure favored HTS (risk ratio [RR] = 0.39; 95% CI = 0.18-0.81). Serious adverse events were not reported. Conclusions: Based on limited data, clinically important differences in mortality, neurological outcomes, and ICP reduction were not observed between HTS or mannitol in the management of severe TBI. HTS appears to lead to fewer ICP treatment failures.

Agreement of measured and calculated serum osmolality during the infusion of mannitol or hypertonic saline in patients after craniotomy: a prospective, double-blinded, randomised controlled trial

Background

Mannitol and hypertonic saline are used to ameliorate brain edema and intracranial hypertension during and after craniotomy. We hypothesized that the agreement of measured and calculated serum osmolality during the infusion of hypertonic saline would be better than mannitol. The objective was to determine the accuracy of serum osmolality estimation by different formulas during the administration of hyperosmolar agent.

Methods

A prospective, randomized, double-blinded, controlled trial was conducted in a 30-bed neurosurgical intensive care unit at a university hospital. Thirty-five adult patients requiring the use of hyperosmolar agents for prevention or treatment of brain edema after elective craniotomy were enrolled, and randomly assigned 1:1 to receive 125 mL of either 20 % mannitol (mannitol group) or 3.1 % sodium chloride solution (hypertonic saline group) in 15 min. Serum osmolality, serum sodium and potassium concentration, blood urea nitrogen and blood glucose concentration were measured during the study period. The primary outcome was the agreement of measured and estimated serum osmolality during the infusion of the two experimental agents. We used Bland and Altman’s limits of agreement analysis to clarify the accuracy of estimated serum osmolality. Bias and upper and lower limits of agreement of bias were calculated.

Results

For each formula, the bias was statistically lower in hypertonic saline group than mannitol group (p < 0.001). Within group comparison showed that the lowest bias (6.0 [limits of agreement: −18.2 to 30.2] and 0.8 [−12.9 to 14.5] mOsml/kg in mannitol group and hypertonic saline group, respectively) was derived from the formula ‘2 × ([serum sodium] + [serum potassium]) + [blood urea nitrogen] + [blood glucose]’.

Conclusions

Compared to mannitol, a better agreement between measured and estimated serum osmolality was found during the infusion of hypertonic saline. This result indicates that, if hypertonic saline is chosen to prevent or treat brain edema, calculated serum osmolality can be used as a reliable surrogate for osmolality measurement.

Trial registration

ClinicalTrials.gov identifier: NCT02037815

Correlation of measured and calculated serum osmolality during mannitol or hypertonic saline infusion in patients after craniotomy: a study protocol and statistical analysis plan for a randomised controlled trial

INTRODUCTION

Brain oedema is a major complication after craniotomy. Hyperosmolar agents have been used as the medical treatment for this condition. Measurement and estimation of serum osmolality during hyperosmolar agent infusion is of clinical importance to evaluate clinical efficacy, adjust dosage and avoid side effects. However, several studies have shown that calculated serum osmolality may lead to a systematic bias compared with direct measurement. In the present study, mannitol or hypertonic saline (HS) will be used in patients after elective craniotomy. We aim to determine the accuracy of serum osmolality estimation during the application of hyperosmolar agent.

METHODS AND ANALYSIS

The study is a prospective, randomised, double-blinded, controlled, parallel-group design. Adult patients requiring the use of hyperosmolar agents for the prevention or treatment of postoperative brain oedema are enrolled and assigned randomly to one of the two treatment study groups, labelled as 'M group' and 'HS group'. Patients in the M and HS groups receive intravenous infusion of 125 mL of either 20% mannitol or 3.1% sodium chloride solution, respectively. Data will be collected immediately before the infusion of study agents, 15, 30, 60, 120, 240 and 360 min after the start of infusion of experimental agents, which includes serum osmolality, concentration of serum sodium, potassium, urea and glucose. Serum osmolality will be measured by means of freezing point depression. Estimated serum osmolality will also be calculated by using four formulas published previously. Osmole gap is calculated as the difference between the measured and the estimated values. The primary endpoint is the correlation of measured and estimated serum osmolality during hyperosmolar agent infusion.

ETHICS AND DISSEMINATION

The study was approved by the International Review Board (IRB) of Beijing Tiantan Hospital, Capital Medical University. Study findings will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT02037815.

Traumatic Brain Injury pathophysiology and treatments: early, intermediate, and late phases post-injury

Traumatic Brain Injury (TBI) affects a large proportion and extensive array of individuals in the population. While precise pathological mechanisms are lacking, the growing base of knowledge concerning TBI has put increased emphasis on its understanding and treatment. Most treatments of TBI are aimed at ameliorating secondary insults arising from the injury; these insults can be characterized with respect to time post-injury, including early, intermediate, and late pathological changes. Early pathological responses are due to energy depletion and cell death secondary to excitotoxicity, the intermediate phase is characterized by neuroinflammation and the late stage by increased susceptibility to seizures and epilepsy. Current treatments of TBI have been tailored to these distinct pathological stages with some overlap. Many prophylactic, pharmacologic, and surgical treatments are used post-TBI to halt the progression of these pathologic reactions. In the present review, we discuss the mechanisms of the pathological hallmarks of TBI and both current and novel treatments which target the respective pathways.